Sarah Keith-Lucas
Weather presenter

The bitter temperatures will be a significant feature of the storm with the US National Weather Service warning that "life-threatening cold air" will slowly track from the High Plains and Rockies in an eastward direction bringing snow and ice to around 200 million people across 30 states.

Further north in central southern Canada daytime highs will be around -25C in Winnipeg.

But you have to take into account wind chill, and the Canadian weather service has warnings of wind chill temperatures of -45C in some areas. The US weather service also has that risk for the northern Plains.

In central US locations like St Louis in Missouri daytime temperatures will drop to -10C, and only 5C in Houston, Texas, which is well below the seasonal average.

Winter snow has made its way into Oklahoma this morning, as a major storm hits the majority of the United States over the weekend.

Tulsa International Airport in Tulsa County is covered in a blanket of snow, and snow ploughs are working to clear the roads in the city of Sand Springs.

More than 10,000 US flights have been cancelled over the weekend as the winer storm begins to grip America.

More than 3,500 flights have been cancelled today, according to flight tracker FlightAware, and more than 6,500 flights scheduled for Sunday are also cancelled.

In Dallas-Fort Worth International Airport in Texas, more than 1,000 flights have been cancelled while more than 400 flights have been cancelled at Charlotte Douglas International Airport in North Carolina.

Some carriers like Delta Airlines, external and American Airlines, external are offering passengers the option to change their flights, in some cases without incurring extra fees, due to concerns about cancellations.

Image source, ANGELA WEISS / AFP via Getty Images

New York City Mayor Zohran Mamdani tells residents to expect "whiteout or near blizzard conditions", with intense cold, a prolonged period of frigid temperatures and "at least eight or nine inches of snow and likely more".

"Frankly, it will be colder than any sustained period that New York has experienced in about eight years," says Mamdani.

Parks have been presalted, major roadways and highways have been brined, and the city continues to be under "code blue" to protect the homeless from freezing conditions, he adds.

Hundreds of snow plough vehicles and salt spreaders are ready to be deployed, and he warns those living in the city to stay indoors.

Image source, Getty Images

More than 84,000 customers are without power across the US as the storm hits.

According to tracking website PowerOutage.com, more than 43,000 customers are without power in Texas, while over 6,000 are affected in Louisiana.

More than 5,000 customers are affected in Arkansas and around 4,000 in California are also without power.

It's not entirely clear whether the storm is the cause of all the power cuts, but officials and forecasters have been warning about the storm's threat to the power network.

Image source, EPA

Heavy snow is forecast across the Southern Rockies and Plains, stretching into the Mid-Atlantic and reaching the Northeast. Some areas could see more than 1ft (30cm) of snow.

Parts of northeast New Jersey and southeast New York, including New York City, could get between 10 and 14in of snow from early Sunday through to Monday, according to the National Weather Service. Wind chills as low as -23C (-10F) are expected in the same region from Friday evening to Saturday afternoon.

Most of southern New England, including Boston, can expect 12 to 17in of snow and wind gusts up to 30mph from Sunday into Monday. Wind chill temperatures there could drop to -26C from Friday into Saturday.

Low temperature records are likely to be broken, with the coldest wind chills possibly falling below -46C across the Northern Plains.

A much wider area of the south-eastern US is also expected to see freezing temperatures.

More than 200 million Americans are facing a brutal winter storm this weekend, with heavy snow, freezing rain and below-zero temperatures set to hit a large part of the East Coast and Midwest.

The National Weather Service says the storm will bring "extremely dangerous" conditions, with at least 16 states under a state of emergency since it began on Friday.

Memphis, Nashville, Washington DC, Baltimore, Philadelphia and New York are among the cities expected to be blanketed with snow.

Regions that could see more than a foot of snow stretch from Colorado to West Virginia, New York City and up to Boston, according to the National Weather Service (NWS).

The NWS also says travel disruption, prolonged power cuts and widespread tree damage are likely.

We're tracking the storm and will bring you the latest updates. Stay with us.